• Title/Summary/Keyword: centrifugally atomized powder

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Stable In-reactor Performance of Centrifugally Atomized U-l0wt.%Mo Dispersion Fuel at Low Temperature

  • Kim, Ki-Hwan;Kwon, Hee-Jun;Park, Jong-Man;Lee, Yoon-Sang;Kim, Chang-Kyu
    • Nuclear Engineering and Technology
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    • v.33 no.4
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    • pp.365-374
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    • 2001
  • In order to examine the in-reactor performance of very-high-density dispersion fuels for high flux performance research reactors, U-l0wt.%Mo microplates containing centrifugally atomized powder were irradiated at low temperature. The U-l0wt.%Mo dispersion fuels show stable in- reactor irradiation behaviors even at high burn-up, similar to U$_3$Si$_2$ dispersion fuels. The atomized U-l0wt.%Mo fuel particles have a fine and a relatively uniform fission gas bubble size distribution. Moreover, only one of third of the area of the atomized fuel cross-sections at 70a1.% burn-up shows fission gas bubble-free zones, This appears to be the result of segregation into high Mo and low Mo.

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A Study on the Powder Structure of Rapidly Solidified HSLA Steels. (급냉응고한 HSLA강의 분말조직에 관한 연구)

  • Nam, Tae-Woon
    • Journal of Korea Foundry Society
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    • v.7 no.2
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    • pp.133-139
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    • 1987
  • The evolution of microstructures in two rapidly solidfied niobium microalloyed steels was studied. These alloys were rapidly solidified by two powder process techniques: nitrogen gas atomization and centrifugal atomization. It was found that in both powder processes, powder particles larger than $20{\mu}m$in diameter were martensitic, and that the nitrogen gas atomized particles solidified cellularly while those that were centrifugally atomized tended to solidify dendritically. Particles smaller than $1{\mu}m$ were not completely characterized because of wide variation in composition.

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Modelling for the Flying and Cooling Behaviors of the Centrifugally Atomized Particles (원심분무 입자의 비산 및 냉각 모델링)

  • 김형섭
    • Journal of Powder Materials
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    • v.3 no.1
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    • pp.25-32
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    • 1996
  • Flying and solidification behaviors of the particles manufactured by centrifugal atomization were investigated. Both models were solved by the explicit FDM. Flying calculation supported the experimental results that the finer particles flied shorter than coarser particles and that particles flied shorter for lower rotation velocity than for higher velocity. Cooling curve and dendrite arm spacing were predicted by use of heat transfer analysis.

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Effects of SiC Cluster on Mechanical Properties of the 2024A1/$SiC_p$ Composites (2024A1/$SiC_p$복합재료의 기계적특성에 미치는 SiC클러스터의 영향)

  • 김홍물;천병선
    • Journal of Powder Materials
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    • v.8 no.2
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    • pp.124-130
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    • 2001
  • A centrifugally atomized 2024A1/SiC/sub p/ composites were extruded to study effect of clusters on mechanical properties, and a model was proposed that the strength of MMCs would be estimated from the load transfer model approach that taken into consideration of the clusters. This model has been successfully utilized to predict the strength and fracture toughness of MMCs. The experimental and calculated results show coincidence and that the fracture toughness decreases with increasing the volume fraction of particles. On the basis of experimental observations, we suggest that the strength and fracture toughness of particle reinforced MMCs may be calculated from; σ/sub y/=σ/sub m/V/sub m/+σ/sub r/(V/sub r/-V/sub c)-σ/sub r/V/sub c/, K/sub IQ/=σ/sub Y/((3πt)((r/sub r//V/sub r/)(r/sub c//V/sub c/))/sup 1/2/)/sup 1/2/, respectively.

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